<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width,initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="app"></div>
</body>
    <script src="https://unpkg.com/vue@next"></script>
    <script>
        const app = Vue.createApp({
               template:`
               <div @click="handleChangeClick" >切换 </div>

               <common-demo  />
               <async-common-demo />
               
               `,
              
            })
            app.component('common-demo',{
               
                template:`
                <div>hello vue.js !</div>
                `
            })
            app.component('async-common-demo',Vue.defineAsyncComponent(() =>{
                return new Promise((resolve,reject) => {
                    setimeout(() => {
                        resolve({
                            template: `
                            <div> the is an async Component</div>
                        `
                        })
                    },3000);
                })

            }))


           app.mount("#app");
    </script>
</html>